High speed image selecting method and digital camera having high speed image selecting function

ABSTRACT

In a digital camera operation method, photographic images are taken with the camera and a corresponding compressed high resolution image and also a corresponding lower resolution image is stored for each. A fast display mode of the camera sequentially displays individual lower resolution display images, using the data of one of the lower resolution images. A normal display mode displays high resolution display images by expanding and displaying one of the compressed high resolution images. When changing from the fast display mode to the normal display mode, the lower resolution display image currently displayed can be replaced with the corresponding high resolution display image.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/717,453 filed Dec. 17, 2012, which is a continuation of U.S.application Ser. No. 12/533,600 filed Jul. 31, 2009, now U.S. Pat. No.8,350,947, issued Jan. 8, 2013, which is a continuation of U.S.application Ser. No. 10/199,320, filed Jul. 22, 2002, now U.S. Pat. No.8,237,840, issued Aug. 7, 2012, which is a divisional of U.S.application Ser. No. 09/059,330, filed Apr. 14, 1998, now U.S. Pat. No.6,445,412, issued Sep. 3, 2002, which are incorporated by reference,herein, in their entirety.

BACKGROUND OF THE INVENTION

The present invention is related to a digital camera, and morespecifically, directed to a high speed image selecting method and adigital camera equipped with a high speed image selecting function, bywhich an enlarged thumbnail image is fed in fast-forward/fast-backwardmodes when an image is displayed on a display unit such as a liquidcrystal display.

Very recently, digital cameras (electronic still image cameras) havebeen developed, and are commercially available, and thus are graduallypopularized.

A digital camera is arranged as follows. Imaging (photographing) lightis photoelectrically converted into image data, and this image data isrecorded on a recording medium, and thereafter is outputted to anexternal image processing apparatus, for instance, a personal computer.Then, the image data is processed by way of a printing image dataforming process in the external image processing apparatus, and then theformed printing image data is outputted to a printer, so that aphotographed image is printed/reproduced on a print paper.

It should be noted that the most digital cameras are equipped withliquid crystal displays (LCD) for displaying photographed images and thelike. On the other hand, image data acquired by photoelectric convertingoperation are compression-processed to be recorded on recording media.Normally, the compression process operation is carried out based on theJPEG (Joint Photographic Image Coding Experts Group) standard (will bereferred to as “JPEG compression” hereinafter).

In the case that an image is selected on the side of a personalcomputer, a plurality of thumbnail images are previously acquired to bedisplayed on a monitor, and a user selects a desirable image. Then, theselected image data is acquired from a digital camera to be expanded,and the expanded image is displayed on the monitor. After this expandedimage is confirmed by the user, this image is processed by executing acolor printing image data forming process, and then this processed imageis printed out by a printer connected to the personal computer.

A thumbnail image corresponds to a compressed image which is used when adesirable image is selected from image data acquired by a personalcomputer and the like. Assuming now that a data size (namely memorycapacity) of image data for 1 frame is equal to 1,024×768 pixels, athumbnail image corresponding to this 1-frame image is such a compressedimage having approximately 86×60 pixels by thinning image data from this1-frame image data. Then the thumbnail image is recorded on a recordingmedium of a digital camera.

In such a system that a digital camera is connected to a communicationline and a wireless (radio) unit such as a portable telephone so as totransmit desirable image data via either a wire line or a wireless line,and/or in order to directly transmit printing image data from thedigital camera to a printer to be printed out, this system should bearranged in a manner that the images are reproduced on a liquid crystaldisplay on the side of the digital camera so as to select a desirableimage.

However, since the image data have been JPEG-compressed to be stored inthe recording medium, these JPEG-compressed image data stored in thisrecording medium should be read out and then be expanded, and thereafterbe extended over a frame memory in order to reproduce/display the imageson the liquid crystal display.

When expanding means for compressed data is constituted by a hardwarecircuit, expanding/extending process time of these compressed data maybe shortened. However, in popularized digital cameras, expanding meansare normally arranged in a program form (will be referred to as an“expanding program” hereinafter) so as to reduce product cost. In suchpopularized digital cameras, 2 to 3 seconds are necessarily required toexpand a 1-frame image (1,024×768 pixels) which has been JPEG-compressedby using this expanding program.

As a result, there is a problem that users have such feelings that imagedisplay time would be prolonged. Moreover, when a desirable image isselected, image data must be sequentially read out to be displayed.Under such a circumstance, if a desirable image is stored in a laterorder, then a long time duration is actually required in order to selectthis desirable image. Thus, there is a further problem that such alengthy access time is practically inconvenient.

SUMMARY OF THE INVENTION

The present invention has been made to solve the above-describedproblems, and therefore, has an object to provide a high speed imageselecting method, and also a digital camera equipped with a high speedimage selecting function, capable of enlarging a thumbnail image to feedthe enlarged thumbnail image in a fast mode.

To achieve these and other objects, a high speed image selecting method,according to a first aspect of the present invention, is featured bysuch a high speed image selecting method for selecting an imagephotographed by a digital camera, comprising the steps of: enlarging andfeeding the enlarged thumbnail images sequentially infast-forward/fast-backward modes to be sequentially displayed; and whena desirable thumbnail image is selected from the enlarged thumbnailimages under display, extending compression image data corresponding tothe selected thumbnail image so as to acquire image data.

In this first aspect, the thumbnail image is fed in thefast-forward/fast-backward modes to be displayed in a high speed. Aftera desirable thumbnail image is selected, the compressed image data isexpanded, so that the image can be selected in a high speed.

In accordance with a second aspect of the present invention, in the highspeed image selecting method of the first aspect, the enlarged thumbnailimages are indexed, and then the enlarged thumbnail images with theindexes are sequentially fed in the fast-forward/fast-backward modes tobe sequentially displayed.

In this second aspect, the thumbnail images with the indexes areenlarged and the enlarged thumbnail images are fed in thefast-forward/fast-backward modes, so that the image can be furthereasily selected.

In accordance with a third aspect of the present invention, a digitalcamera equipped with a high speed image selecting function is featuredby that in a digital camera for recording on a recording medium, imagedata produced by photoelectrically converting photographing light andthumbnail image data thereof, a digital camera equipped with a highspeed image selecting function, comprising: a display unit fordisplaying an image; data expanding means for expanding compressed imagedata; thumbnail enlarged image display means for enlarging thumbnailimage data and for displaying the enlarged thumbnail image data on thedisplay unit; thumbnail image selecting means for feeding the enlargedthumbnail image under display in fast-forward/fast-backward modes toselect a desirable thumbnail image; image display means for displayingimage data corresponding to the selected thumbnail image on the displayunit; and selection image defining means for defining the displayedimage as a selection image.

In this third aspect, the thumbnail image is fed in thefast-forward/fast-backward modes to be displayed in a high speed. Aftera desirable thumbnail image is selected, the compressed image data isexpanded, so that the image can be selected in a high speed.

In accordance with a fourth aspect of the present invention, a digitalcamera equipped with a high speed image selecting function is featuredby that the fast-forward/fast-backward feeding operations of theenlarged thumbnail image by the thumbnail image selecting means arecommenced by executing a predetermined switch operation.

In accordance with the fourth aspect, the enlarging process and thefast-forward/fast-backward feeding operations of the thumbnail image canbe readily realized by a predetermined switch operation, so that thethumbnail images can be selected in a high speed.

A digital camera equipped with a high speed image selecting functionaccording to a fifth aspect of the present invention, is featured bythat in the digital camera equipped with the high speed image selectingfunction, as described in the third aspect or the fourth aspect, thefast-forward/fast-backward feeding operations of the enlarged thumbnailimage by the thumbnail image selecting means are commenced when aninstruction is issued such that forward/backward feeding operations ofnormal image data are continuously performed within a predetermined timeperiod.

In accordance with the fifth aspect, when the image selection iscontinuously performed within a predetermined time period, the operationis automatically transferred to the enlarging operation and thefast-forward/fast-backward operations of the thumbnail image, so thatthe thumbnail image can be readily selected in a high speed. Also, sincethe enlarged thumbnail image is displayed until the image data isdisplayed, the waiting tension given to the user can be relaxed.

A digital camera equipped with a high speed image selecting function,according to a sixth aspect of the present invention, is featured bythat in the digital camera equipped with the high speed image selectingfunction, as described in the third aspect, the fourth aspect, or thefifth aspect, the expanding process of the image data by the dataexpanding means is carried out in conjunction with the display processof the enlarged thumbnail image corresponding thereto.

According to the sixth aspect, since the enlarging/display processoperation of the thumbnail image and the expanding process of the imagedata are carried out, the image data can be quickly displayed after theselecting operation.

A digital camera equipped with a high speed image selecting function,according to a seventh embodiment of the present invention, is featuredby that the digital camera equipped with the high speed image selectingfunction, as described in any one of the preceding aspects 3 to 6, isfurther comprised of: indexing means for indexing the enlarged thumbnailimage displayed by the thumbnail enlarged image display means. Inaccordance with the seventh embodiment, since the enlarged thumbnailimages are indexed, the image selection by thefast-forward/fast-backward operation can be readily performed.

A recording medium, according to an eighth aspect of the presentinvention, is featured by such a recording medium readable by a digitalcamera for recording on the recording medium, image data produced byphotoelectrically converting photographing light and also thumbnailimage data thereof, on which a program is recorded and the program iscapable of realizing: a data expanding function for expanding compressedimage data; a thumbnail enlarged image display function for enlargingthe thumbnail image data and for displaying the enlarged thumbnail imagedata on a display unit; a thumbnail image selecting function for feedingthe enlarged thumbnail image under display in fast-forward/fast-backwardmodes to select a desirable thumbnail image; an image display functionfor displaying the expanded image data corresponding to the selectedthumbnail image or the display unit; and a selection image definingfunction for defining the displayed image as a selection image.

Since the program recorded on the recording medium according to theeighth aspect of the present invention is executed, the enlargedthumbnail image can be fed in the fast-forward/fast-backward operations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1( a) and 1(b) is a block diagram for showing a structural exampleof a digital camera equipped with a high speed image selecting functionaccording to an embodiment of the present invention;

FIG. 2 is a block diagram for representing a structural example of highspeed image selecting means;

FIGS. 3( a) and 3(b) show a rear surface portion of the digital camera;

FIGS. 4( a) and 4(b) are explanatory diagrams for explaining a pixelinterpolation method (simple interpolation method);

FIG. 5 is a flow chart for describing an example of operation of thehigh speed image selecting means;

FIG. 6 is a flow chart for describing an example of operation of thehigh speed image selecting means; and

FIG. 7 is a flow chart for describing an example of operation of thehigh speed image selecting means.

DETAILED DESCRIPTION

FIGS. 1( a) and 1(b) are block diagrams for representing a structuralexample of a digital camera according to an embodiment of the presentinvention.

In FIG. 1( a), a digital camera 100 is constructed of an optical systemmade of a lens and a diaphragm, for entering reflection light reflectedfrom an imaging object onto a CCD 2; a CCD 2 for converting the imaginglight projected from the optical system 1 into an electric signal; andan image data forming unit 3 for processing the electric signal derivedfrom the CCD 2 to be supplied as raster data (image data) of multiplevalues (R, G, B) to a frame memory 12A. Furthermore, the digital camera100 is arranged by a control unit 4, an input means 5, a moving picturedisplay control unit 6, an image data output unit 7, a recording mediumcontrol unit 8, a built-in recording medium 9, an enlarged recordingmedium 10, an interface 11, an LED lamp 15 functioning as a displaymeans, and a liquid crystal display 16.

In this digital camera, the control unit 4 controls the executions ofthe operation controls, the image processing operations, and the imagecompressing/expanding process operations of the image data forming unit3, the moving picture display control unit 6, the image data output unit7, the recording medium control unit 8, and the high speed imageselecting means 60. The input means 5 is constituted by a button and aswitch. The input means 5 inputs an instruction made by a user bymanipulating these button and switch, and converts the instruction intoa digital signal which will be then supplied to the control unit 4.

The moving picture display control unit 6 outputs the image data to theliquid crystal display 16 so as to display the moving picture. In thisembodiment, the image data stored in the frame memories 12A and 12B aredisplayed in a superimpose manner during the normal display mode.Normally, it should be noted that the image data are written into theframe memory 12A predetermined times, for example, 30 times, or 60 timesper 1 second by the image data forming unit 3, and the image isdisplayed on the liquid crystal display 16 under control of the movingpicture display control unit 6 in synchronism with the writing operationof the image data in the same phase.

In the case that a specific button is depressed while displaying amoving picture to instruct an image recording operation, the image dataoutput unit 7 converts the R, G, B raster data saved in the frame memory12A into a luminance component Y, and color difference components U andV. Also, the image data output unit 7 subjects to these luminance/colordifference components to the JPEG-compression, and further executes acompression process operation for producing a thumbnail image.

Upon receipt of the image data outputted from the image data output unit7, the recording medium control unit 8 controls a writing operation suchthat JPEG-compressed image data (simply will be referred to as “imagedata” hereinafter) and compressed image data are written into apredetermined position of the built-in recording medium 9, or theenlarged recording medium 10, and also controls a reading operation ofeach of the recorded JPEG image data.

The built-in recording medium 9 and the enlarged recording medium 10 areprovided to store thereinto the image data. A serial interface, or aparallel interface 11 is employed to transmit/receive data to/from anexternal apparatus. Also, the LED lamp 15 displays a condition of aswitch, and a functional specification. The liquid crystal display 16displays a photographed image, or an object to be imaged.

Normally, the frame memory 12A is used as an image display memory of theliquid crystal display 16. The image data is extended in this framememory 12A as a bit map image. The frame memory 12B is employed as amenu display memory, if required. Then, when an image is displayed onthe liquid crystal display 16, the storage contents of the framememories 12A and 12B are displayed in a superimposed manner, ifrequired.

In this embodiment, the built-in recording medium 9 is constructed of a4 MB (Megabytes)-flash memory fixed inside the camera 100. Not only theimage data, but also other data such as a program are stored into thebuilt-in recording medium 9. In this embodiment, as the enlarged storagemedium 10, a 4 to 45 MB-memory card is utilized. In this case, althougha memory card interface (PCMCIA interface or ATA interface: not shown)is employed, the present invention is riot limited thereto, but othercard type memories such as a compact flash (a trade mark of Sun DiskInc.) may be utilized.

FIG. 1( b) represents an arrangement of the control unit 4. The controlunit 4 is arranged by a CPU 41, a RAM 42, and a ROM 43. In this ROM 43,a program group has been previously stored, which is required to executea data process operation within the digital camera 100, for example, theoperation control of the digital camera 100, and the datacompressing/expanding process operations.

Also, the digital camera 100 transmits the image data stored in thebuilt-in recording medium 9 via the interface 11 to an externalapparatus, for instance, a computer unit. The digital camera 100communicates the image data via the modem 300. Furthermore, in such acase that a printing image data forming process program group is savedin the digital camera 100, printing image data is formed. Then theprinting image data may be directly transmitted to a printer 400 so asto print out the image.

FIG. 2 is a schematic block diagram for showing a structural example ofthe high speed image selecting means 60 which may constitute a majorportion of the digital camera according to the present invention. Thehigh speed image selecting means 60 is constituted by a thumbnailcompression image data expanding means 61, a thumbnail imageenlarging/displaying means 62, a thumbnail image selecting means 63, acompression image data expanding means 64, an image display means 65,and a selected image defining means 66.

It should be understood that the high speed image selecting means 60according to this embodiment is constituted by software. Alternatively,the high speed image selecting means 60 formed in the software may bearranged to be stored in the ROM 43. Otherwise, the high speed imageselecting means 60 recorded on an external recording medium as asoftware form may be acquired to be saved into the recording medium 9.When the high speed image selecting means 60 is executed, this highspeed image selecting means 60 formed in the software may be transferredto the RAM 42.

The thumbnail compression image data expanding means 61 cause thethumbnail image data to be acquired into the RAM 42 so as to execute theexpanding process operation of the compressed thumbnail image data, andthen extends the expanded thumbnail image data into the RAM 42. Since apixel number of a thumbnail image is small, even when all of thethumbnail images are expanded, a total time duration to execute thisexpanding process thereof is extremely shorter than the expanding timeof the image data. It should also be noted that in such an image processsystem that no compression process operation is performed to thethumbnail image data, this thumbnail compression image data expandingmeans 61 is no longer required.

The thumbnail image enlarging/displaying means 62 enlarges the expandedthumbnail image data, and transfers the enlarged thumbnail image data tothe frame memory 12A so as to extend the enlarged thumbnail image dataas a picture image. Then, the thumbnail image enlarging/displaying means62 causes either an enlarged thumbnail image 31 or an enlarged thumbnailimage 35 to be displayed as an enlarged image on the liquid crystaldisplay 16 (FIG. 3( a) and FIG. 3( b)).

In this case, when a thumbnail image is simply enlarged to be displayed,intervals among adjoining pixels become coarse, so that the overallimage is blurred. As a consequence, it is preferable to display such athumbnail image produced by interpolating an enlarged image (see FIGS.4( a) and 4(b)).

When the button provided near the liquid crystal display 16 ismanipulated by the user, the thumbnail image selecting means 63 judgesthe implication of this button manipulation, and scrolls the enlargedthumbnail image 31 or 35 within the display screen in order that adesirable image by the user is specified.

When the enlarged thumbnail image is displayed, the compression imagedata expanding means 64 acquires image data corresponding to thisenlarged thumbnail image from the recording medium so as to expand thisacquired image data to thereby extend the expanded image data.

The image display means 65 transfers the image data extended in the RAM42 to the frame memory 12A, and then extend this transferred image dataas a picture image to thereby display this picture image on the liquidcrystal display 16. As a result, the expanding process operation of theimage data is accomplished, which is specified while the enlargedthumbnail image displayed in the above-described manner is observed bythe user. Then, the specified/expanded image data is overwritten intothe enlarged thumbnail data, so that clear image data can be displayed.

When the button provided near the liquid crystal display 16 ismanipulated by the user, the selected image defining means 66 judges theimplication of this button manipulation, and will execute a subsequentprocess operation when this button manipulation instructs the definitionof the selected image.

For the sake of an easy explanation, the thumbnail compression imagedata expanding means 61 is separately provided with the compressionimage data expanding means 64. However, since the image data to beexpanded are different from each other, both the thumbnail compressionimage data expanding means 61 and the compression image data expandingmeans 64 may be arranged to employ the same data expanding means, forexample, may be arranged as a subprogram.

Also, the above-described high speed image selecting means 60 may beemployed so as to not only select the image in the digital camera, butalso select the image of the digital camera acquired by the personalcomputer.

Now, a description will be made of a pixel interpolating method that canbe employed by the thumbnail image enlarging/displaying means 62.

Typically, there are the linear interpolation method and the simpleinterpolation method (FIGS. 4( a) and 4(b)) as a pixel interpolatingmethod. The present invention may employ any of these interpolationmethods.

In the linear interpolation method, a resolution conversion is carriedout by performing a linear interpolation between adjoining two points,so that resolution with a predetermined level can be maintained.

To the contrary, the simple interpolation method is such aninterpolation method that, as indicated in FIGS. 4( a) and 4(b), whilepositions of original pixels A, B, C, and D after being enlarged arecalculated, assuming now that a magnification is selected to be “R” and“S” (both R and S are positive integers), the original pixels are copied(R−1) times along the X directions. After the copying operations of theoriginal pixels along the X direction are accomplished, the originalpixels are copied (S−1) times along the Y direction to fill theintervals among these original pixels.

In other words, as shown in FIG. 4( a), while an origin is set as theoriginal pixel “A”, if an image constituted by original pixels A(0,0),B(0,1), C(1,0), and D(1,1,) located adjacent to each other is firstenlarged 4 times along the X direction, and then is enlarged 5 timesalong the Y direction, then positions of the original pixels A, B, C,and D after being enlarged become A(0,0), B(0,5), C(4,0) and D(4,5) (seeFIG. 4( b)). Then, the original pixels A, B, C, and D are copied only 3(=4−1) times along the X direction so as to fill the intervals. When thecopy operations of the original pixels along the X direction areaccomplished, the column is copied only 4 (=5−1) times along the Ydirection. As a result of this operation, as represented in FIG. 4( b),the pixels enlarged by the magnification of 4×5 are formed on the bitmap.

In accordance with the linear interpolation method, gradation betweentwo points may be calculated, and gradation of an enlarged image can bemaintained at a certain level. As a consequence, the image qualityachieved by this linear interpolation method is better than thatachieved by another interpolation method. However, when the linearinterpolation calculation is performed by employing a computer, acomplex dividing calculation is required except for a specific case, sothat a lengthy processing time period is needed. To the contrary, aprocessing time period by in the simple interpolation method requiresthe shortest time. However, since the gradation is not adjusted but alsopixels are simply copied, the image quality is coarse. The larger theenlargement ratio becomes, the lower the quality of the enlarged imageis rapidly decreased. Accordingly, there is a limitation that theenlargement ratio by the simple interpolation method is selected to beon the order of 4 times.

In accordance with this embodiment, the size of the screen of the liquidcrystal display 16 employed in the digital camera 100 is limited, aridis substantially equal to a size of a thumbnail image×4 times. As aconsequence, there is no problem as to the image quality. Moreover,since the interpolation speed achieved by this simple interpolationmethod is faster than that of another interpolation method, the enlargedthumbnail image is interpolated by employing the simple interpolationmethod. It should be understood that when a higher image quality of adisplayed image is required, the linear interpolation method ispreferably employed.

FIG. 5 is a flow chart for indicating an example of operations of thehigh speed image selecting means. It is assumed that as an initialcondition, both the thumbnail image data and the image data have beensubjected to the JPEG-compression and the JPEG-compressed image datahave been recorded on the recording medium 9. As indicated in FIG. 5,when either the button 19 or the button 20 is depressed to commence thehigh speed image selection, the thumbnail compression image dataexpanding means 61 acquires the thumbnail image data into the RAM 42,and then expands the JPEG-compressed thumbnail image data to extend theexpanded thumbnail image data into the RAM 42 (step S1). Subsequently,the thumbnail image emerging/displaying means 62 sequentially givesindex numbers to the expanded thumbnail image (namely, image with imagenumber 31 in FIG. 3( a)), and then enlarges/interpolates the thumbnailimage data with the index number (namely, simple interpolation method inthis embodiment). Thus, the interpolated thumbnail image data isdisplayed as an enlarged thumbnail image on the liquid crystal display16 (step S2). Also, when the user depresses the button 19 or the button20, the high speed image selection process operation is returned to thestep S1 (step S3: YES).

While the button 20 (fast-forward button) provided near the liquidcrystal display 16 is continuously depressed by the user, the thumbnailimage selecting means 63 repeats the process operations defined at thesteps S1 and S2 to successively display the thumbnail images on theliquid crystal display 16 (fast-forward) in the increment order.Conversely when this button 20 is released by the user, the display ofthis thumbnail image is stopped.

The button 19 is the fast-backward button. While this fast-backwardbutton 19 is continuously depressed by the user, the thumbnail imageselecting means 63 repeats the process operations defined at the stepsS1 and S2 to successively display the thumbnail images on the liquidcrystal display 16 (fast-backward) in the decrement order. When thisbutton 19 is released by the user, the display of this thumbnail imageis stopped.

When the image stop time duration has passed for a predetermined timeperiod (2 seconds in this embodiment), it is assumed that this image isspecified as the selected image. Then, the process operation is advancedto the next step S4 (step S3: NO).

At a step S4, when the enlarged thumbnail image is displayed, thecompression image data expanding means 64 acquires the image datacorresponding to this enlarged thumbnail image from the RAM 42 to expandthis acquired image data, and then extends the expanded image data intothis RAM 42. Subsequently, the image display means 65 transfers theimage data extended in the RAM 42 to the frame memory i2A so as to beextended as the picture image. Then, the image display means 65overwrites this extended image data on the liquid crystal display 16(step S5).

When either the button 17 or the button 18 is depressed by the user, theselected image defining means 66 executes the “next process” (step S6:YES). When either the button 19 or the button 20 is depressed by theuser, the process operation is returned to the step 51 (step S7: YES).

Alternatively, in such a case that even when a predetermined time period(for example, 6 seconds) has passed, either the button 19 or the button20 is not depressed at the step 6, the selected image defining means 66may be arranged to execute the “next process”.

It should be understood that as the “next process” after the image isselected by the high speed image selecting means 60, there are apreparation process operation and a printing image data forming processoperation. In this preparation process operation, this image data istransmitted via the wireless line, or the wire line. In this printingimage data forming process operation, the printing data is formed inorder to directly print out the image by the printer. These processoperations may be executed by another program separately introduced intothe digital camera 100.

FIG. 6 is a flow chart for indicating an example of operations of thehigh speed image selecting means. It is assumed that as an initialcondition, both the thumbnail image data and the image data have beenJPEG-compressed and the JPEG-compressed image data have been recorded onthe recording medium 9.

In the example of FIG. 5, when the last-forward key button 20 and thefast-backward key button 19 are depressed, the fast-forward operationand the fast-backward operation are commenced. In this example, thenormal reproducing operation is carried out at the first stage. Wheneither the button 19 or the button 20 is continuously depressed under apredetermined condition, the operation mode is transferred to the highspeed image selection mode.

That is, when the normal reproducing operation is carried out (stepS11), if either the button 19 or the button 20 is depressed (step S12:YES), then the compressed image data expanding means 64 acquires onepreceding image data, or one succeeding image data into the RAM 42, andexpands/extends these acquired image data. Subsequently, the imagedisplay means 65 transfers the image data extended in the RAM 42 to theframe memory 12A so as to extend this image data as a picture imagewhich is displayed on the liquid crystal display 16 (step S13).

In this case, if the same button is depressed at the time when the imagereproducing operation is completed (step S14: YES), the processoperation is advanced to the high speed image selection mode. Thethumbnail compression image data expanding means 61 acquires thumbnailimage data corresponding to one preceding image data, or the onesucceeding image data into the RAM 42, and then expands theJPEG-compressed thumbnail image data to extend the expanded thumbnailimage data into the RAM 42. Subsequently, the thumbnail imageenlarging/displaying means 62 enlarges/interpolates the expandedthumbnail image data (namely, simple interpolation method in thisembodiment). Thus, the interpolated thumbnail image data is displayed asan enlarged thumbnail image on the liquid crystal display 16 (step S15).

In such a case that the button is further continuously depressed whenthis display of the enlarged thumbnail image is completed (step S16:YES), the process operation is returned to the step S14 at which Onepreceding thumbnail image, or one succeeding thumbnail image is enlargedto be displayed. While the button is continuously depressed, thisprocess operation is repeatedly carried out, so that the high speedimage selection can be realized.

On the other hand, when depressing of the button is stopped (step S16:NO), the enlarged thumbnail image is displayed, the compression imagedata expanding means 64 acquires the image data corresponding to thethumbnail image under display from the RAM 42 to expand this acquiredimage data, and then extends the expanded image data into this RAM 42.Subsequently, the image display means 65 transfers the image dataextended in the RAM 42 to the frame memory 12A so as to be extended asthe picture image. Then, the image display means 65 overwrites thisextended image data on the liquid crystal display 16 (step S17). Then,the process operation is returned to the step S12.

While the operations of the high speed image selection process have beendescribed, switching of the normal reproduction operation and the highspeed selection reproduction operation may be executed by manipulating apredetermined switch, otherwise by any other manners.

FIG. 7 is a flow chart for indicating an example of operations of thehigh speed image selecting means. It is assumed that as an initialcondition, both the thumbnail image data and the image data have beenJPEG-compressed and the JPEG-compressed image data have been recorded onthe recording medium 9.

In the example of FIG. 6, when the fast-forward/fast-backward keybuttons 19/20 are continuously depressed under a predeterminedcondition, the process operation is advanced to the high speed selectionmode. In this example, when either the button 19, or the button 20 isfirstly depressed from the normal reproducing condition, the normalreproducing operation is carried out. The process operation is advancedto the high speed selection mode after the second process operation.

In other words, when the normal reproducing operation is executed (stepS21), a check is made as to whether or not a selection key of a menu isdepressed (step S22). When the selection key is not depressed (step S22:YES), after a menu process is executed (step S23), the process operationis returned to the step S22. On the other hand, when the button 19, orthe button 20 is depressed (step S24: YES) while the selection key isnot depressed (step S22: NO), since the first button manipulation isexecuted, the compressed image data expanding means 64 acquires onepreceding image data, or one succeeding image data into the RAM 42, andexpands/extends these acquired image data. Subsequently, the imagedisplay means 65 transfers the image data extended in the RAM 42 to theframe memory 12A so as to extend this image data as a picture imagewhich is displayed on the liquid crystal display 16 (step S25).

Next, in such a case that either the button 19 or the button 20 is notdepressed for a predetermined time period, e.g., 1 second or 2 second(step S26: NO, step S27: YES), the process operation is returned to thestep S22. Conversely, when either the button 19 or the button 20 isdepressed within a predetermined time period (step S26: YES), since thisis the second key manipulation, the process operation is advanced to thehigh speed image selection mode. The thumbnail compression image dataexpanding means 61 acquires thumbnail image data corresponding to onepreceding image data, or the one succeeding image data into the RAM 42,the thumbnail image data into the RAM 42, and then expands theJPEG-compressed thumbnail image data to extend the expanded thumbnailimage data into the RAM 42. Subsequently, the thumbnail imageenlarging/displaying means 62 enlarges/interpolates the thumbnail imagedata (namely, simple interpolation method in this embodiment). Thus, theinterpolated thumbnail image data is displayed as an enlarged thumbnailimage on the liquid crystal display 16 (step S28).

After the display of this enlarged thumbnail image is accomplished, ifthe button is not depressed within a predetermined time period, forexample, 1 second, or 2 seconds (step S29: YES), then the processoperation is returned to the step S28 at which either one precedingthumbnail image or one succeeding thumbnail image is enlarged to bedisplayed. When the button is continuously depressed within apredetermined time period, this process operation is repeatedlyperformed, so that the high speed image selection can be realized.

On the other hand, when the button is not depressed for predeterminedtime period (step S19: NO, step S30: YES), the compression image dataexpanding means 64 acquires the image data corresponding to thisenlarged thumbnail image from the RAM 42 to expand this acquired imagedata, and then extends the expanded image data into this RAM 42.Subsequently, the image display means 65 transfers the image dataextended in the RAM 42 to the frame memory 12A so as to be extended asthe picture image. Then, the image display means 65 overwrites thisextended image data on the liquid crystal display 16 (step S31). Then,the process operation is returned to the step S22.

In FIG. 7, when the fast-forward/fast-backward keys are depressed afterthe normal image reproducing operation, the operation mode is advancedto the high speed selection mode after the second key operation.Alternatively, a predetermined flag may be set by executing the firstkey operation during the first process operation and the second processoperation, so that the first and second process operations can bediscriminated from the process operations subsequent to the secondprocess operation. Also, the operation mode is forcibly advanced to thehigh speed selection mode when the second process operation is carriedout. Alternatively, after the first key manipulation, when apredetermined time period (for example, 1 to 3 seconds) has passed, itmay be judged that the first key manipulation is again carried out.

While the operations of the high speed image selection process have beendescribed, switching of the normal reproduction operation and the highspeed selection reproduction operation may be executed by manipulating apredetermined switch, otherwise by any other manners.

Although the various embodiments of the present invention have beendescribed, the present invention is not limited to the above-explainedembodiments, but may be modified, substituted, or changed.

As previously described in detail, according to the present invention,the thumbnail images are enlarged to be displayed so as to select adesirable image. While this desirable thumbnail image is displayed inthe enlarge form, the image data corresponding to this thumbnail imageis expand-processed, and thus the clear image can be displayed. As aconsequence, even when a predetermined time duration is required toexpand the JPEG-compressed image of 1 frame, the user does not havelengthy time feelings of the image display. Also, since the thumbnailimage can be fed in the fast-forward/fast-backward modes, the desirableimage which is recorded on the recording medium in the later order canbe selected within a short time period.

As described above, the storage of the data captured during the takingof a photographic image may include the storing of the compressed highresolution image, and the storing of a corresponding lower resolutionimage. Although referred to herein as “thumbnail”, the lower resolutionimage need not be limited to a thumbnail, but can be a so-calledscreen-nail or other type of lower resolution image. For the sake ofgenerality, any such lower resolution image referred to above using theterm “thumbnail” should be understood to mean any image of lowerresolution than the corresponding high resolution image that was takenin the photographic operation.

It will also be appreciated that the sequential showing of individuallower resolution images may be thought of as a fast display mode. Itwill also be understood that the showing of a display image by expandingthe compressed high resolution image and displaying it may be thought ofas a normal display mode.

What is claimed is:
 1. An apparatus comprising: a user instructionreceiver configured to receive a first user instruction and a seconduser instruction; a display unit: configured to display a first screenfor displaying a low resolution image; when the user instructionreceiver receives the first user instruction, configured to change thelow resolution image on the first screen; and when the user instructionreceiver receives the second user instruction, configured to select alow resolution image on the first screen and to change from the firstscreen to a second screen for displaying a high resolution imagecorresponding to the selected low resolution image; and a controllerconfigured to, after changing to the second screen, execute apreparation process to transmit image data corresponding to the highresolution image on the second screen via a wireless line.
 2. Theapparatus according to claim 1, wherein after executing the preparationprocess, the image data can be transmitted via the wireless line.
 3. Theapparatus according to claim 1, wherein the display unit is configuredto change the low resolution image on the first screen by a scrollingoperation which corresponds to the first user instruction.
 4. Theapparatus according to claim 1, wherein the display unit is configuredto change the low resolution image, one by one, on the first screen by ascrolling operation which corresponds to the first user instruction. 5.The apparatus according to claim 1, wherein the display unit isconfigured to display the first screen for displaying the low resolutionimage without displaying the high resolution image, and wherein thedisplay unit is configured to display the second screen for displayingthe high resolution image without displaying the low resolution image.6. The apparatus according to claim 1, wherein a pixel number of the lowresolution image is smaller than a pixel number of the high resolutionimage.
 7. The apparatus according to claim 1, further comprising: animaging element configured to produce the image data based on imaginglight, wherein the low resolution image and the high resolution imageare produced based on the image data.
 8. A method of displaying an imageand transmitting data, the method comprising: displaying a first screenfor displaying a low resolution image; when receiving the first userinstruction, changing the low resolution image on the first screen; whenreceiving the second user instruction, selecting a low resolution imageon the first screen and changing from the first screen to a secondscreen for displaying a high resolution image corresponding to theselected low resolution image; and after changing to the second screen,executing a preparation process to transmit image data corresponding tothe high resolution image on the second screen via a wireless line.